Nasa has received a signal from Voyager 2 after an error caused the space agency to lose contact with the craft for nearly a fortnight.
Flight controllers sent the wrong command to the space probe nearly two weeks ago, accidentally tilting its antenna away from Earth and severing contact.
After days of silence, Nasa finally heard from Voyager 2 - which is billions of miles away in interstellar space - on Tuesday.
Nasa’s Deep Space Network, made up of giant radio antennas across the globe, picked up a “heartbeat signal”, meaning the 46-year-old craft is alive and operating, project manager Suzanne Dodd said on Tuesday.
Ms Dodd said the news had “buoyed our spirits”.
Flight controllers at the Jet Propulsion Laboratory in California will now try to turn Voyager 2’s antenna - which is just two per cent off-kilter - back toward Earth.
If the command does not work - and controllers doubt it will - they will have to wait until October for an automatic spacecraft reset.
Ms Dodd added: “That is a long time to wait, so we’ll try sending up commands several times [before then].”
Voyager 2 rocketed into space in 1977, along with its identical twin Voyager 1, on a quest to explore the outer planets.
Still communicating and working fine, Voyager 1 is now 15 billion miles (24 billion kilometres) from Earth, making it the most distant spacecraft.
Voyager 2 trails its twin in interstellar space at more than 12 billion miles (19 billion kilometres) from Earth.
At that distance, it takes more than 18 hours for a signal to travel one way.
